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SPECIES BARRIERS. The next sections feature an extraordinary paper written in 2000 about the leaky species barrier, if any, in prokaryotes, a precursor to a lengthy and important paper on biological dark matter. Both papers are paradigm shifts with old thinking, heretical tomes. Both papers are unashamedly abstracted. View in LinkedIn

NON-RANDOM VARIATION. “The above insights derive from different fields, but fit together with surprising coherence. They show that variation is not random, that there is more to inheritance than genes, and that there are multiple routes to the fit between organisms and environments.” An important paper. https://lnkd.in/gninbRv View in LinkedIn

“STANDARD EVOLUTIONARY THEORY has long regarded inheritance mechanisms outside genes as special cases; human culture being the prime example. The Extended Evolutionary Synthesis explicitly recognizes that parent–offspring similarities result in part from parents reconstructing their own developmental environments for their offspring. ‘Extra-genetic inheritance’ includes the transmission of epigenetic marks (chemical changes that alter DNA expression but not the underlying sequence) that influence fertility, longevity and disease resistance across taxa.” http://www.nature.com/news/does-evolutionary-theory-need-a-rethink-1.16080 View in LinkedIn

NOISE VERSUS SIGNAL. “In essence, Standard Evolutionary Theory treats the environment as a ‘background condition’, which may trigger or modify selection, but is not itself part of the evolutionary process. It does not differentiate between how termites become adapted to mounds that they construct and, say, how organisms adapt to volcanic eruptions. We view these cases as fundamentally different.” http://www.nature.com/news/does-evolutionary-theory-need-a-rethink-1.16080 View in LinkedIn

NOT ONLY RANDOM VARIATION. “Differences in the diets and conditions of fish living at the bottom and in open water have induced distinct body forms, which seem to be evolving reproductive isolation, a stage in forming new species. The number of species in a lineage does not depend solely on how random genetic variation is winnowed through different environmental sieves. It also hangs on developmental properties that contribute to the lineage’s ‘evolvability’.” https://lnkd.in/gninbRv View in LinkedIn

NICHE ADAPTATION CAUSES SPECIATION. “Studies of fish, birds, amphibians and insects suggest that adaptations that were, initially, environmentally induced may promote colonization of new environments and facilitate speciation. Some of the best-studied examples of this are in fishes, such as sticklebacks and Arctic char.” https://lnkd.in/gninbRv View in LinkedIn

PLASTICITY FIRST. “The key finding here is that plasticity not only allows organisms to cope in new environmental conditions but to generate traits that are well-suited to them. If selection preserves genetic variants that respond effectively when conditions change, then adaptation largely occurs by accumulation of genetic variations that stabilize a trait after its first appearance. In other words, often it is the trait that comes first; genes that cement it follow, sometimes several generations late.” https://lnkd.in/gninbRv View in LinkedIn

IMPORTANCE OF PLASTICITY. “Standard Evolutionary Theory views this plasticity as merely fine-tuning, or even noise. The Extended Evolutionary Synthesis sees it as a plausible first step in adaptive evolution.” http://www.nature.com/news/does-evolutionary-theory-need-a-rethink-1.16080 View in LinkedIn

NEW FINDINGS. “Expanding multilocus sequence typing (MLST) surveys now show that it is often homologous recombination—not the stepwise accumulation of mutations after separation of lineages—that accounts for the lion's share of sequence differences between isolates.” https://lnkd.in/djKBnru View in LinkedIn

RARE COMBINATION EVENTS? “Bacterial population geneticists have known for some time that prokaryotic genomes do sometimes recombine, but early estimates suggested that rates of recombination were sufficiently low to be ignored when considering periodic selection events.” https://lnkd.in/djKBnru View in LinkedIn